"It's regrettable, but I think it's a case where a lot of extremists have taken over the Republican Party and one of their complaints about me was that I support Obamacare. That's unethical to say that," McCain told the site.

McCain said the state GOP reprimand "fires me up" as he weighs whether to run for re-election in 2016, when he would be 80 years old.

"We've got polling data that shows overwhelming support. I've won every election in Arizona by very large margins, quite often with the opposition of [the right flank] of the party," Politico reported.

The state GOP said McCain, an Arizona Republican, has a "long and terrible record of drafting, co-sponsoring, and voting for legislation best associated with liberal Democrats, such as amnesty, funding for Obamacare, the debt ceiling, liberal nominees, assaults on the Constitution and Second Amendment," the resolution read.

McCain responded that he had "led the fight for 25 days on the floor of the Senate" against Obamacare.

He opposed the conservative strategy of closing down the government in October 2013 rather than allowing any spending bill that funds the Affordable Care Act to pass.

He said that Republicans would be blamed for any shutdown and warned: "I know how the movie ends: We don't defund Obamacare until we have 67 Republicans in the United States Senate," Politico reported.

Meanwhile, former Alaska Gov. Sarah Palin, McCain's vice presidential running mate, came to his defense in a Monday Facebook posting: "I consider Senator John McCain an American hero and a friend. He fights to remind our president that the federal government's first priority must be strong defense of our homeland, and ... he fights against big-spending colleagues who don't prioritize for our military’s needs," The Washington Post reported.

Palin said that while they did not agree on all the issues, including immigration reform and the debt, Palin said she found it "perplexing" that McCain's efforts to block the Obama agenda had been ignored and possibly undermined by his opponents to the right in Arizona.